Added Jest test suite

src/test/App.test.js

@@ -0,0 +1,16 @@
+import React from "react";
+import { render, screen } from "@testing-library/react";
+import "@testing-library/jest-dom";
+import { Provider } from "react-redux";
+
+import store from "../store/";
+import App from "../components/App";
+
+it("renders an option to view categories", () => {
+  render(
+    <Provider store={store}>
+      <App />
+    </Provider>
+  );
+  expect(screen.getByText("Categories")).toBeInTheDocument();
+});